Described embodiments relate generally to an apparatus, commonly referred to as a shotgun stick, for manipulating and installing clamps and other devices to electrical connectors, and more particularly to a shotgun stick for use at extended distances from the electrical connectors.
Linemen working on electric power distribution systems often have to manipulate, remove and install clamps and other devices to electrical connectors. To perform these tasks, a lineman may use apparatus, commonly referred to as hot sticks, designed to electrically insulate the potentially energized electrical connector from the lineman, and to provide structure for manipulating the clamps. Hot sticks are commonly made from materials, for example wood or fiberglass, that do not conduct electricity along their lengths sufficient to cause harm to a workman when the sticks are energized at substantial voltages, such as fifty thousand to one hundred thousand volts.
It may be difficult for the lineman to get close to the electrical connector for performing tasks. For example, the electrical connectors may be electric power lines, or may be located at electric power lines, mounted high in the air, for example on poles or on the sides of buildings. Lift platforms or buckets, mounted on trucks, are used to elevate and position the lineman closer to the connector. However, environmental or other conditions may restrict or prevent positioning the truck, or the bucket, for the lineman to work close to the connector. The restrictive conditions may include, for example, soft or steep terrain, or the presence of trees or vines. In some instances, the lineman may be required to climb the utility pole to access the lines or devices. Accordingly, the hot sticks come in various lengths, or are designed to have adjustable lengths, to allow the lineman to manipulate the clamps or other devices from a distance, for example from a bucket lift, from the utility pole, or from the ground.
Certain tasks performed with hot sticks require that the clamp or other device be grasped firmly, to secure it and give the lineman control over it. Examples of those tasks include: changing out k-mates and fuses; isolating jumpers; and installing and removing arresters, risers, fault indicators and bird guards. Those tasks may typically be performed with a kind of hot stick commonly referred to as a shotgun stick, clamp stick or grip-all stick. Shotgun sticks include clamping mechanisms operated by the lineman to firmly grasp the clamp and other devices. Examples of shotgun sticks are described in U.S. Pat. Nos. 3,666,311 and 3,788,691, and 5,096,438. Shotgun sticks typically come in fixed or adjustable lengths of about six feet to about eight feet. FIG. 20 shows a known fixed length shotgun stick, for example a standalone, manual shotgun stick.
Shotgun sticks are typically used while the lineman is standing in the truck lift, and sometimes when the lineman is on the pole. Shotgun sticks are typically not used from the ground to perform tasks at elevated locations, which may be up to fifty feet or more above the ground level. Sticks that long may experience significant bowing over their lengths, caused by the weight of the stick itself and of the grasping mechanism at the stick's working end. The bowing inhibits the required mechanical operation of the grasping mechanism by the lineman, which operation is typically effected by an actuating rod extending along the length of the stick. Making the hot stick stiffer to decrease the bowing over such extended lengths, adds more weight to the stick, making it impractical to lift and maneuver by the lineman.
Other tasks do not require firm grasping of the clamp or other device. Examples of those tasks include opening and closing cutout doors for housings for fuses for mainline or transformers. Those tasks may be performed with shotgun sticks, or they may be performed with other hot sticks that do not have a clamping mechanism for grasping the device, but, rather, may have a fixed hook or other working end configuration, for example for engaging cutout door handles. Those hot sticks may include a working end attachment attached to a hot stick support rod, or pole. The support rod may have a fixed length or may be adjustable. FIG. 23 shows a known fixed-length hot stick pole with no working end attachment. FIG. 16 shows a known un-extended telescoping pole 1600 with a working end attached. FIG. 18 shows example known hot stick working end attachments and connector mount configuration, including a tree trimmer 1810, a standard switch head disconnect 1820, a non-metallic disconnect 1830, and a plastic universal mount configuration 1840. Some known adjustable hot stick support rods are commonly referred to or available as pogo sticks, tel-o-poles, or extendo sticks, and may extend to greater lengths than known shotgun sticks. Extendo sticks may typically telescope to lengths up to forty-five to fifty-five feet, and are typically used while the lineman is standing on the ground.
When there is a power failure, customers lose electrical service and a first responder lineman may be dispatched to identify the cause of the failure. If the first responder lineman can fix the problem, the customer power may be restored quickly. Sometimes, the first responder lineman cannot fix the problem because the failed equipment is out of reach of the lineman and of his tools, for example a shotgun stick. Thus, other workmen and/or a bucket truck may be required before the lineman may reach the failed equipment, using a bucket truck or by climbing a pole. For inaccessible poles, it may be necessary to take more difficult measures, such as using mats or “winching” a truck in, to get a truck close enough to the pole to perform the tasks, which measures increase the risk of injury and increase outage and cost, particularly in afterhours situations.
Accordingly, there is a desire for devices and methods that provide a shotgun stick for performing tasks at extended distances without having to climb poles or use a bucket.